Our Dirty Little Secret
by n1c0le
Summary: What if Derek and Casey actually ARE together on the show but it's a secret that they hide from everybody? Dasey, with a little bit of DE and CS.
1. Chapter 1

**Author's Note: **_I know, I know... another Dasey fic by moi lol. I just can't help myself, I keep getting these new fic ideas that just beg to be written. I've had this idea for awhile... I thought about what if Derek and Casey actually ARE together, but we just don't see it in the show because they are trying to fool everybody (their family, friends, the audience...). I know, very very improbable. BUT, it sparked the idea for this fic in my head. So here it is... it should end up being a few chapters long... if you guys all like it, that is. So, let me know what you think, and if you want me to continue it, I will :-) _

* * *

Derek twitched a bit as he watched Sam take Casey's hand. He tried to act like it didn't bother him that they were together. Casey was his in secret. In public, though, Casey was with Sam, and Derek was with Emily. Nobody had a clue about the stepbrother and stepsister's hidden affair.

Casey had actually been the one to bring up appearance, surprisingly. Since everyone would freak out if they saw Casey and Derek together, they had to keep is hush-hush. And she was also the one to come up with the idea that they should stay with their "significant others." Sam and Casey had been going out for about 6 months, and Derek and Emily had been together for about 2 months.

He didn't know why he was even going out with Emily. Sure, she was fun sometimes. But he definitely didn't feel the way she obviously did. He wanted to break up with her. But it was hard enough watching Casey and Sam together. It would be even worse if he didn't have anyone himself.

He looked over at Emily as they sat on the bus. Then he realized she had been talking to him.

"Derek?" she looked at him expectantly.

He shook himself and forced a smirk. "Sorry, babe." He didn't even bother making an excuse.

Emily sighed, pursing her lips together and taking his arm. He didn't feel anything, unlike the sparks that he felt when Casey touched him. "What's the matter, honey? You've been spacing a lot lately."

Probably since he and Casey had started their torrid affair, a couple of weeks ago. She had consumed his every thought ever since.

"Uh, I just have a lot on my mind lately," he shrugged. "Hockey stuff, mostly."

"Aww," Emily said empathetically, stroking his arm. "You've been working hard, baby. All that practicing."

Some of the times he had made up these "practices," just so he could avoid going out with her. He didn't feel bad about it.

Derek nodded. He glanced over at Casey and Sam again, sitting a few rows away from them. Sam was talking to Casey and she was laughing, her nose wrinkling and smile bright. She looked really good today. It had been a school field trip to an art museum, and she had dressed up a bit for it. She was in a pair of tight black pants and a button down top, the outfit hugging all of her curves so perfectly. Her hair was half-off of her face, which Derek liked so he could see her deep blue eyes. She must have felt his eyes on her because her eyes shifted suddenly from Sam to Derek. She gave him a slight, almost imperceptible smile, and quickly looked back at Sam.

Derek gulped slightly, suddenly itching to get home and have Casey all to himself.

"…shopping?" Emily looked at him.

Shit. She had been talking again.

"Uh…yeah," Derek said, not even knowing what she had asked him.

Emily grinned brightly. "Great! I'll meet you there at five."

"Huh?" Derek's eyebrows furrowed. What had he gotten himself into?

"Meet me at the mall, silly," she smiled. "At five."

Derek inwardly kicked himself. And he had already used the "hockey practice" excuse three times this week. If he used it again, she might start to get suspicious.

"Fine," Derek wasn't happy about it at all. It meant less Casey Time. And he hated shopping.

Emily laid her head on his shoulder and he looked out the window, wondering how much longer it would take to get back to school.

* * *

As soon as they got back to school, Derek hurriedly left, not even bothering to go to his locker. He needed to leave quickly before Emily asked him to walk her home or something. He made it home before Casey, even though she usually got dropped off by Sam, who now had a car. Derek didn't think his best-friend was at all better than him because he could drive and Derek still had another month before he could get his license.

"Hi, Derek," Nora said to him as he walked into the kitchen to grab a soda. She was rolling some dough. "How was school?"

"Fine," he said simply and opened a can of Pepsi. He gulped half of it down quickly, the caffeine-filled liquid refreshing him from the boring day he had at the museum.

"How about the museum?" Nora asked as if she had read his mind.

"Boring," he answered.

Nora gave a short laugh. "Didn't you learn anything?"

"Yeah, that some famous artists really shouldn't be famous," he scoffed.

Nora laughed again, shaking her head at her stepson. Just then, Casey walked in. Her eyes and Derek's eyes met quickly.

"Casey, honey, how did _you_ like the museum?" Nora asked her daughter.

Casey drew her eyes away from Derek's. "Umm…it was nice." She smiled. "The art work was beautiful."

"Two different opinions, as expected," Nora concluded. Then she said to them, "I'm baking cookies now. They should be done soon. Why don't you two go start on some homework and I'll call you when they're done?"

"Sounds good," Casey said quickly, heading for her bedroom. She gave Derek an expectant look.

Derek glanced at Nora, moving over in Casey's direction, "Uh, yeah, call us." He said shortly and the two of them went into the living room and up the stairs quickly.

As soon as they got to the top of the stairs, Casey pulled Derek to her, a big smile on her face.

"Hey," she said, eyes shining. Their mouths were millimeters apart.

Derek grinned. "Hey yourself." He crashed his lips upon hers.

Casey moaned happily, pulling Derek down the hall and into her bedroom. He kicked the door shut once they were in, and the two of them fell onto Casey's bed.

Derek closed his eyes, enjoying the feeling of Casey under him and his lips on hers. His tongue slid into her mouth and she moaned again, wrapping her legs around him, pulling him closer to her.

"I have to go out with Sam tonight," Casey gasped out to him as he moved his lips to her neck.

She sounded a little annoyed about it. Derek liked that.

"Yeah, I have to go out with Em," Derek said, his voice raspy against her soft skin. He pulled away and Casey gave him a little pout.

"We're not gonna have much time together tonight," she reached up and ran her hands through his messy brown hair.

He thought for a second. "Well, I'm gonna try to get out of staying too long with Emily. So you just come see me when you get home."

She smiled a bit, "Wow, that's actually a good idea. Who knew you were smart?" she teased.

He gave her a mock offended look and she giggled, wrapping her arms around him. "I'm just kidding," she murmured, pressing her lips back against his.

"Casey! Derek!" Nora suddenly called. "Come down for cookies!"

The two groaned synchronously.

Derek went in for Casey's lips again, but she pushed him away gently, laughing. "Derek, we don't want her coming up here. Plus I could use a sugar rush before my date."

Derek groaned and got up off of her. She sat up and fixed her hair before they headed towards the kitchen.

"So where are you and Sam going?" he asked casually.

"The movies and dinner," she replied. "It's for him to make up forgetting our sixth month anniversary." She rolled her eyes, clearly not over that.

Derek nodded. Even he had remembered that it was her and Sam's anniversary last week. I mean, how could he forget?

They went into the kitchen to find Nora, Marti, Edwin, and Lizzie all sitting at the kitchen table eating chocolate-chip cookies.

"Smerek! Have a cookie!" Marti offered, pointing at the plate in the middle of the table.

"I will, Smarti," he grinned at his little sister, taking a cookie and sitting down next to the bouncing girl.

Casey smiled to herself, watching Derek with Marti. He loved how the two were so close. Derek was so sweet with her.

"Are you going to have one, Case?" her own sister asked her.

Casey looked over at Lizzie, breaking out of her daze. Her cheeks pinked as Derek glanced up at her, knowing she had been staring at him. She nodded and sat down quickly next to her.

Derek gave her a slightly cocky smile, having caught her.

After their snack, Casey went upstairs to get ready for her date, and Derek played some video games with Edwin for awhile. Not too long after, the doorbell rang. Derek opened it, and, as expected, it was Sam.

"Hey, man," Derek said to him. He had been hanging out much less with him in the past few weeks.

"Hey," Sam replied. They did their usual best-friend male hand shake thing.

"Is Casey ready?" he asked, looking around the room as if she was there.

"I'll go check," Derek told him, gladly leaving the room. He jogged upstairs and didn't even bothering knocking on Casey's door. She was sitting at her make-up mirror, finishing up her lipstick. She had on a short skirt and a bra, having not wanted to risk getting make-up on her shirt because it was white.

Casey gasped when he came in. "Derek!" she breathed. "You have to knock."

"I do?" he leered at her. She looked great sitting there half-dressed. He stared at her white push-up bra in lust.

She sighed, seeing what he was staring at. She a slight smile graced her lips. "You've seen them before."

He had. Some of their make-out sessions got pretty hot and heavy. They hadn't gone all the way yet, but it had come pretty close. So seeing Casey in a bra was nothing new. But he enjoyed it all the same.

"So?" he winked. She smiled and went back to finishing her make-up. He walked over to her.

"Your date's here," he told her, trying not to seem bitter about it. He wrapped his arms around her from the back and began kissing the side of her neck.

"Mmm…" Casey closed her eyes briefly at the feeling.

He didn't want her to go on the date. Hell, he didn't want her to be dating Sam at all. He wanted her all to himself.

"Derek, I've got to go," she giggled, not making any real attempt to push him away, though. He pressed gentle kisses down her shoulder.

"Then go," he dared her to move as he gently moved his hands up her sides. He moved his lips back up to her neck and watched her lips part as he kissed his way down her spine from the nape of her neck. Her bare skin was soft and warm. Casey shivered.

He began tugging at her bra, and she laughed, finally swatting him away. "Get out of here!" she gave him a bright smile.

He grinned sheepishly.

She stood up and he watched her pull on her white top. He didn't like how tight and low-cut it was… for a date with Sam, anyway.

She grabbed her purse. "I'll see you tonight," she smiled, pressing a kiss to the corner of his mouth before exiting the room.

Derek stood there, disappointed. He sighed and looked over at the clock. It was almost 5:00. He should be heading to the mall, anyway.

He groaned and left the house. Emily ran over to him as soon as he got there. He was twenty minutes late, but she didn't say anything about it.

"Hey, baby!" she smiled and kissed him deeply. She wasn't a bad kisser, but didn't even compare to Casey.

Emily clung to his arm for the entire night. She made him go into the stupidest girly stores that he hated.

"Do you wanna go to a movie?" Emily asked, hugging him to her as they stood near a bench. There was a movie theatre in the mall.

Derek looked up at the titles of what was playing. There was a movie he wanted to see. It was a guy movie that he knew Emily would never want to see. "Only if I can pick the movie," he smirked down at her.

"Okay," she kissed him and dragged him to the theatre. As they were walking in, they literally bumped right in to Casey and Sam.

"Casey!" Emily exclaimed gleefully. "What are you doing here?"

Casey and Derek stared at each other for a split moment, surprised to see each other.

"Oh, we're on a date," Casey gave a half-smile up at her boyfriend, whose arm was around her waist.

Derek stared at Sam's arm, thinking of how he didn't deserve to be touching Casey. Feeling jealous, and hating that feeling, he pulled Emily closer to him.

"So are we," Emily grinned up at Derek. "Hey, we should double date sometime!"

Derek's eyes widened. "Uh…I don't think that's such a good idea."

"Yeah, we have totally different schedules, I don't think it would work," Casey added. She noticed Emily's hands all over Derek and tried not to look annoyed with that, which she was.

"I think it would be fun," Sam shrugged in his relaxed way.

"Great," Emily said. "How about tomorrow night?"

"I'm free," Sam nodded, and looked down at his girlfriend.

Casey gave a fake smile. "Yeah…sure…"

"Fine," Derek mumbled, knowing this was going to be a bad idea.

"Awesome!" Emily was just way too chipper. "Wouldn't it be easier if we just got together right after school?"

"Sure," Casey said through her teeth.

"Sounds cool," Sam said. He looked down at Casey again. "We should get going, Case. I made reservations for us."

Casey looked pleasantly surprised. Derek looked down at his feet.

"Have fun you two!" Emily called as they left. She squeezed Derek's arm. "They're so cute. Now, what are we going to see?"

It turns out that Derek should have left Emily pick the movie instead. He now had five half-moon shaped nail marks on his upper arm. She had screamed in his ear several times, too. Derek couldn't wait to drop her off at home.

"That was fun, Derek," Emily smiled as she stood at her door.

"Yeah," Derek said halfheartedly.

She kissed him and they said good night. Derek scuffed his sneakers against the pavement as he walked home in the dark.

He went right up to his bedroom and booted up the computer. There, he sat and waited for Casey. _His_ Casey.


	2. Chapter 2

**Author's Note: **_Hmm... well, I don't seem to be getting that great of a response to this story so I'm not sure if I should keep going... let me know what you think. But anyway, here's the next chapter!_

* * *

Around 10:00, Casey's curfew time, he heard someone walking up the stairs. He hoped it was her. And then the door opened and she appeared like apparition in the night. Their eyes met and Casey smiled, shutting the door behind her. She kicked off her heels and slinked over to Derek, sitting down comfortably on his lap. 

Derek pulled her close against him. He kissed the side of her forehead as she rested against his chest.

"Did you have fun on your date?" he asked, the bitterness coming through in his voice.

She raised her eyebrows up at him. "It was alright." She sat up again and wrapped her arms around his neck. "Are you jealous?" she asked playfully, turning so she was now straddling him and looking deep into his dark eyes.

"No," he mumbled, now avoiding her gaze.

"You _are_!" she exclaimed with a smile. She took his chin in her hand and forced him to look at her. He unwillingly got lost in her blue eyes.

She searched his eyes and smiled. Wordlessly, she captured his lips and Derek closed his eyes as the sparks took over. She pushed herself against him and he groaned at his growing feeling of desire.

"And how was your date with Emily?" she asked, removing her mouth from his and beginning to nibble on his ear.

He could barely concentrate enough to know what his name was when she was doing that, never mind answer her questions. He tried hard to think, but all he could do was feel Casey's soft lips and wet tongue on his earlobe.

"Mmmuhh…" was all he could come up with.

Casey giggled softly against his ear. "Really? That good, huh?"

"No…" he closed his eyes again, letting himself simply feel.

Casey buried one hand in his hair as she pulled him in for another kiss. She moaned as their tongues battled.

There was a sudden dinging noise that made the both of them jump. They turned to the computer screen, realizing Derek had just been instant messaged.

It was Sam saying "hey."

"Sorry, man," Derek said, talking to the computer. He got up, taking Casey with him, leading them to his bed. "I can't talk now, I'm making out with your girlfriend."

Casey laughed and hit him playfully. "Derek!"

"What?" he grinned, pulling her down onto the bed with him. "He can't hear me." He captured her lips again to stop her from saying anything else.

"It's really warm in here," Casey whispered against Derek's lips.

"Take off some clothes," he waggled his eyebrows teasingly.

She rose up to his challenge and peeled off her white shirt and then pulled off her skirt. He grinned down at her. She just smiled up at him innocently.

"Aren't you hot?" she asked.

"Yes, _I'm_ _hot_," he teased with a wink. She gladly watched him yank his shirt off. She pressed her hands against his hard bare chest. Hockey players definitely had nice bodies.

"You are," she agreed with him with a happy sigh.

Derek chuckled and leaned in for another kiss. They made out for a little while longer, and then Casey said that she was tired.

"Go to sleep," Derek told her, pressing a kiss against her slightly swollen lips.

"Here?" she asked. She had never slept in his bed.

"Why not? Nobody ever comes in," Derek said. He had the rest of the family trained well. Knock or die.

"Okay," she smiled.

Derek got up, pulled his jeans off, and shut the light. Then he crawled back into bed and pulled the blankets up over the two of them.

"'Night, Derek," Casey cuddled up to his warm body.

Derek held her tightly, a smile playing on his lips in the dark. "'Night, Case."

* * *

Derek woke up with a loud groan, hitting his stupid alarm clock. 

"I don't wanna get up," he heard Casey mumbled and burrow into the blankets.

Derek chuckled at that, wrapping his arm around her. "It's seven o'clock."

Casey jumped at that. "You set your alarm for SEVEN?" she cried out.

Derek raised one eyebrow. "Yeah. I don't take that long to get ready."

"But I do!" she grabbed her clothes and ran out of the room in a tizzy. She was going to be late if she didn't hurry up. In such a rush, she didn't notice Lizzie in the hallway, who had seen her older sister run out of Derek's room in her bra and underwear. Lizzie's eyes widened and she hurried over to Edwin's room.

"Edwin!" she whispered loudly as she simply barged in, not even remembering to knock.

Edwin was dressed and playing with his hair in his mirror, wondering if he should start messing with his dark locks as his brother did. He quickly turned away from the mirror, pretending to not have been fussing with his hair. Lizzie looked too involved with her news, thankfully for Edwin.

"What's up?" Edwin asked coolly, sitting down on his bed.

Lizzie sat down next to him, her blue eyes still widened in surprised confusion. "Edwin, do you know what I just saw?"

Edwin watched Lizzie bite her lip, and he could see her struggling for some kind of answer for what she had just witnessed. So he knew it was something big.

"What?" he didn't even bother guessing. Whatever it was probably wasn't guessable, anyway. Lizzie didn't react like this over nothing.

"I just saw Casey running out of Derek's room in just her underclothes," Lizzie said slowly.

Edwin's eyes widened. He could barely process that. "Wait… _what_?"

Lizzie nodded vigorously. "I saw it with my own eyes! Do you think that they're… you know…?" her eyes met Edwin's.

Edwin could feel himself blushing at the mere thought of sex. "Uh… I don't know. I mean… they couldn't be…" his forehead wrinkled. "…could they?"

"I thought they couldn't stand each other," Lizzie shrugged, shaking her head.

"Maybe we should, you know, look into this," Edwin suggested.

Lizzie eyed him. "Like investigate?"

"More like spy on them," Edwin gave a sly smirk.

Lizzie smiled slowly. She loved when she and Edwin played detective. Last time they had, the two of them had found out what their Christmas presents were.

"Alright."

The two of them exchanged sneaky grins. They would get to the bottom of this Derek/Casey thing.

* * *

Casey almost didn't make it to school in time. She ran into homeroom, her hair in a messy ponytail and her socks mismatched. She sat down in her seat, letting out a huge breath she didn't know she had been holding. 

Emily swiveled around in the seat in front of Casey. "Hey, Case. Almost didn't make it, eh?"

Casey shook her head, exhausted from having sprinted to school. "Well, Derek set the ala—" She stopped, eyes widening as she caught herself. Emily's eyebrows furrowed in confusion.

"Uh, Derek set my alarm clock an hour ahead to mess with me," she quickly covered. "I'm going to kill him after school," she added for good measure.

Emily laughed. "Ah, that sounds like my Derek," she said wistfully. Casey inwardly flinched at that. "Besides, you can't kill him today," Emily continued. "We have our double date tonight!"

Casey tried to suppress her groan. She had forgotten about the double date from hell scheduled for that evening.

"I'm looking forward to it," Emily said brightly.

"Me too," Casey tried to sound honest, but failed miserably. Luckily, Emily wasn't paying attention, as a girl next to her complimented Emily on her new shoes.

Casey dropped her head on to her desk, letting out her suppressed long groan of anguish. She knew tonight was going to be a torture-filled nightmare.

After school, Emily caught up with Derek, much to his displeasure.

"I'm so excited about our double date tonight," Emily grinned, reaching up and kissing him. Then she looked around. "Now, where are Casey and Sam?"

Derek slapped his forehead. He had forgotten that they were getting together right after school. Great…

As if on cue, Casey and Sam appeared. Casey gave Derek a "kill me now!" face when Emily looked away to fix the buckle of her shoe. Derek hid a smirk. It seemed as though she was dreading the date as much as he was.

Emily saw Casey and Sam approaching and let out a girly squeal. "Hey guys! This is going to be SO much fun! I brought some makeup, Case, so we can get all dressed up over your house. You boys can just… watch one of your little sports games or whatever."

Derek looked at her dumbly. "There aren't any sports on at three in the afternoon."

Emily just shrugged. "Whatever. Watch cartoons then, I don't know." She then grinned at Casey. "Case and I have to get prettified."

Derek wanted to laugh at the fake smile Casey gave Emily. Priceless.

They piled into Sam's car, even though the MacDonald-Venturi home really was too close to even bother driving to.

"Sam and his stupid car," Derek thought to himself, rolling his eyes.

As soon as the four of them got to the house, Emily ushered Casey upstairs and Derek was stuck with Sam in the living room. He was supposed to be best friends and all, but Derek felt himself getting more and more distant with Sam… especially now that he and Casey had a thing going on…

"So…" Derek tried to break the awkward silence that ensued as they sat down on the couch. But he really had nothing to say.

"I tried IMing you last night," Sam said.

Derek remembered that. He tried not to smirk cheekily at the memory. "Oh… really? I guess I didn't see it," he lied easily.

Sam shrugged. It wasn't a big deal.

The front door opened and Nora and Marti both walked in. "Hi, boys," Nora smiled, holding a box from the pastry shop down the street.

"Nora got a blueberry pie for dessert, Smerek!" Marti bounced up and down.

Derek smiled at his little sister. "Let me guess… it's blue day."

"Yup!" Marti took off her jacket, revealing her blue shirt and blue skirt. She skipped over to Derek and climbed on to his lap. He always let her.

"I'm not gonna be here for dessert, Smarti," Derek broke the news to her.

Marti looked shocked. "Why not?"

"I'm going out on a date," he told her.

Marti pouted. "But it's blue day!"

"Well… if Nora gets a dessert for red day, I'll definitely be there. You know I love cherry pie," he tickled Marti and she squealed with laughter.

"That can be arranged," Nora smiled at her stepson. She looked down at Marti. "Marti, honey, want to come help me find something blue for you for dinner tonight?"

Marti nodded and quickly followed Nora into the kitchen, leaving Derek and Sam alone in an uncomfortable silence again.

Meanwhile, Casey was actually having a nice time gossiping with Emily upstairs as they put on their make-up.

"…so then I heard that Julie just totally broke down," Emily continued, opening her eyes wide to finish applying her mascara.

"I'm not surprised," Casey shook her head as she brushed her long dark hair.

"Yeah, but can you really blame her? I mean, she was _cheated _on," Emily sighed, putting her mascara down. "Jason was just so low for cheating on her. And with her friend, too!"

Suddenly Casey stopped brushing her hair. She looked away, feeling a sudden pang of utter guilt. She was always such a good girl. She always did the right thing. But now… now she was cheating on her boyfriend, and lying to her best friend. When did things get so complicated?

Casey looked over at Emily. She didn't deserve this. She was a nice friend. Biting her lip, she realized what she had to do. Gathering up her confidence, she opened her mouth. "Em, I—"

"But then again, Jason and Julie were never a great couple to begin with. And he seems so much happier with Anna. So, maybe it was kind of meant to be, you know?" Emily said, continuing with her make-up.

Casey slowly closed her mouth. Maybe, in some strange way, Emily made some sense. Or maybe it was just easier for Casey to pretend that Emily was right…

"So, have you heard anything about Hannah and Matt?" Emily moved on.

* * *

Derek was ready to die of boredom. Either Sam had gotten really boring, or he had always been that boring and Derek had just never noticed it before. It had been well over an hour, and the girls had shown no sign of coming down anytime soon. He was getting restless to just get this stupid night over with. 

"I'm going to go see how much longer the girls are going to be," Derek told Sam, who was watching some boring BMX show.

Sam nodded and Derek sighed heavily, making his way up the stairs. Lazily, he knocked on Casey's door.

"You two almost done?" he asked in an annoyed tone.

"Almost!" Emily called back.

"How much longer?"

"Ummm…" Emily trailed off.

"Like five more minutes!" Casey finished.

Derek groaned. "Hurry up!" he shouted back and then went back downstairs.

Fifteen minutes later, he heard the girls walking down the stairs.

"About ti—" Derek's words just stopped as he turned to look up at the girls. His eyes focused immediately not on his girlfriend, but on Casey. She looked… breathtaking. She had on a tight green top (Derek's favorite color) and a skirt with a slit all the way up her thigh that showed off her long legs. Her make-up wasn't drastic, but since she never wore much, it made her look even more… alluring. Yes, alluring was the word that Derek would use for her. Her hair was scrunched a bit, creating loose waves down her shoulders. She smiled just faintly, but in a tantalizing way. And she was looking right at him, not Sam.

Sam hadn't even turned around yet, so into his program.

"Wow," Derek let out a breath. It was meant for Casey, but Emily giggled.

She went over and took Derek's arm. Derek had to almost physically unglue his eyes from Casey to look down at his own dressed-up girlfriend. She looked good, but didn't hold a candle to Casey.

"Are we ready to go?" Casey asked, hands on her hips as she looked at her boyfriend. Sam hadn't even looked at her.

"Yeah," Sam just said, his eyes still on the TV.

"Where are we going, anyway?" Derek asked Emily, who was the unspoken coordinator of this double date evening.

"I got us reservations at Chez Jaques-Louis," Emily smiled proudly.

Derek inwardly groaned. He hated that expensive French bistro. "Great."

Emily giggled at Derek again, clutching him even more tightly to her. Derek looked up at Casey in desperation. She just gave a small smile, a twinkling in her eyes that made Derek just want to grab her and kiss her breathless. But that's when Sam looked up, shutting the TV off. He raised his eyebrows at Casey.

"You look nice," he said to her.

_Nice_? Derek scoffed to himself. She looked _nice_ when she woke up in the morning, bleary-eyed with her hair tangled and no make-up on. Right now, she looked _amazing_, to say the least.

Casey gave him a short smile. Derek noticed that the smile didn't even reach her eyes. She let him slip his arm around her. Derek looked away.

"Let's go then!" Emily exclaimed giddily.

The four of them walked out and got into Sam's car. Casey sat in the front with Sam, of course, and Derek and Emily got into the back. Derek glanced over at Emily, who was leaning up against him, staring at his profile. It was a bit uncomfortable for him. She just smiled, and when he looked down at her again, she caught his lips in a somewhat sloppy kiss. Casey's eyes met Derek's via the passenger side mirror.

"So, it's on Farceur Ave, right Emily?" Sam asked.

Emily broke the kiss. "Yeah, just by that Tim Horton's off of Main Street."

Casey and Derek both looked out the window, each silently praying that they would be able to make it through the night without giving away their secret.


	3. Chapter 3

**Author's Note: **_Hmm... still not that great of a response, but I wrote another chapter for those who are actually reading lol. Thanks :-) And I hope you enjoy the DATE! Hehe._

* * *

The four of them sat in the fancy restaurant, Emily all bouncy and excited, Sam passive and looking bored as always, and both Casey and Derek looking uncomfortable. They kept sneaking glances at each other behind their menus. 

"What are you gonna get?" Emily batted her eyelashes up at Derek, rubbing his arm sweetly.

Derek casually pulled away his arm, pretending to be thirsty as he reached for his glass of water. "Um, I don't know," he said after taking a sip. He almost spat out his water as he choked on it, feeling a dainty foot brush against his leg seductively. He looked over at Casey, who was sitting directly across from him, a devilish smile on her face.

The waiter came over as Casey foot softly rose up Derek's leg, and Derek had to fight to remain still and calm in his seat like nothing was going on under the table. Casey wanted to rile him up. Sam was being boring and no fun.

"Can I get you all some drinks?" the waiter asked, scratching his moustache indifferently.

"I'll have mineral water with lemon, please," Emily ordered before everyone else. She then smiled over at her boyfriend. "Derek?"

Derek was about to order when he felt Casey's foot graze against… well, a place that you didn't want to toy with when you were in public. He half-gasped, half-yelped, and then grew red as the waiter, Emily, and Sam all looked at him as if I had lost it. Casey simply gave her stepbrother an innocent smile.

"Uh… C-Coke," Derek manage in a stutter, throwing Casey a glare as the waiter jotted his drink preference down.

"Same," Sam nodded up at the waiter. Derek rolled his eyes, swearing to himself that the kid has no mind of his own.

Casey ordered a diet Coke with no ice and looked over at her stepbrother again once the waiter was gone. He was listening to Emily chew his ear off about some school gossip that Derek clearly didn't care about.

She looked over at her own boyfriend, who was studying the menu like he would be given a test on it in just a few minutes. "So… Sam, how's Angela doing?" His oldest sister was pregnant with Sam's first nephew.

"Good," Sam shrugged. He didn't seem nearly as excited as she would be if she was going to be an aunt. Like if Lizzie or Edwin or Marti or Derek was to have a kid.

Casey immediately wrinkled her nose. She didn't want to think about Derek marrying some other woman and having kids with her… having this happy life. Not that she and Derek were really together or anything. It was all a secret. But Casey often wondered… was it meant to be just that? Some secret from their teen years that nobody will ever know?

Derek met Casey's eyes, but she wasn't really looking at him. She looked like she was zoned out, in deep thought. And by the look on her face it wasn't some happy thought, either. He tapped her gently with his foot, giving her a questioning look. She immediately came back to reality and after a pause gave Derek a slight smile.

The waiter came back with their drinks and they all ordered hors d'oeuvres. Derek wasn't thrilled about it; he liked getting right down to the entrée. But Emily insisted that he had to get an hors d'oeuvre, so he ordered a bowl of some stupid soup just to get her off of his back.

Sam and Casey seemed to get into some kind of conversation, but Derek couldn't hear it because Emily was in yet another ramble. He just nodded every once in awhile, willing for the clock to tick faster so he could get out of this hellish date.

Hors d'oeuvres came much too slowly, and Derek occupied himself with his soup, trying to block out Emily's insistent blather. He watched Sam lean in to whisper something in Casey's ear and watched her smile. Not able to take it, he looked away quickly, staring back down into his bowl.

Casey glanced at the delicate silver watch on her wrist every so often, hoping that time would move in double-time or something like that. The way Derek was absently rubbing his soupspoon against his lips was driving her insane. She wanted to grab him and ravage him on the table, but figured that wouldn't be a great idea. Especially because her boyfriend was sitting right next to her, as Derek's girlfriend was next to him.

She never noticed how much Emily talked. Wow, that was getting annoying.

The waiter cleaned up the hors d'oeuvres, and Derek almost cheered when they finally got to order entrées. It meant that they were closer to this stupid date coming to an end.

Derek felt like beating his head against the table until he was knocked unconscious so he wouldn't have to listen to Emily's talking anymore. Just to shut her up, he even resorted to grabbing her and kissing for a long time on the mouth. His ears thanked him for the few moments of quiet.

Casey looked away quickly, feeling twinges of jealousy grab at her heart. She just had to remind herself that Derek would be hers again in just a few hours. All hers.

NOT Emily's.

Casey and Sam engaged in a boring talk about their English teacher, and as soon as Derek released Emily, she joined in the conversation as well. Derek let out a silent groan at hearing her talking again.

The rest of dinner was just as uncomfortable. And just went Casey and Derek both thought it was over, Emily decided that they had to order dessert. Casey wasn't happy about this. Not even chocolate mousse could make her feel better about this whole awkward situation.

So it was another twenty minutes before they could leave. As they were heading out into the dark cool Canadian air, Derek grabbed Casey.

"You have some chocolate on your face," he smirked and, with a risk, leaned into her and gently ran his warm tongue on the side of her mouth, licking the mousse off of her.

She smiled. "Thanks," she whispered, giving him a wink before she went back over to Sam so as to not raise suspicion.

Derek ran his tongue over his lips, savoring the flavor of chocolate-covered Casey.

_That_ put some X-rated images in his head…

"Now we should go see a movie," Emily leaned against Derek as they got into the car.

Derek groaned loudly, not caring who heard. He just wanted this damn date to be over with!

Emily giggled, swatting her boyfriend playfully. "Don't worry; no chick flicks."

Casey let Sam take her hand as they walked into the movie theatre. She could practically see Derek's muscles tightening at the action. She gave him a soft smile, assuring him that it was him she would rather be with, and he seemed to relax just slightly.

Of course, Emily picked the movie since she was the coordinator of this whole nightmare. Derek was just glad that in the cinema, Sam and Emily both took the outside chairs of a row of four in the back of the theatre, leaving Casey and Derek in the middle together.

"I heard this is a great movie!" Emily assured them all excitedly, snuggling against Derek's shoulder. Sam lamely put his arm around Casey as the movie started up. Casey subtly slid one hand over to Derek's chair, finding his hand. He willingly gave his hand up to Casey, letting her soft fingers lace through his larger, rougher ones.

They both smiled to themselves.

Derek and Casey almost forgot to release their hands as the credits began rolling and the lights turned on. Emily had tried to make out with Derek during the movie, but he had skillfully evaded her. Casey had watched this, a highly amused smile on her face. Sam seemed bored, as always.

"Is the date over now?" Derek asked his girlfriend pleadingly. She giggled misinterpreting his tone.

"Don't worry, we'll do this again soon," Emily grinned up at him as they walked back to the car.

"Great," Derek muttered sarcastically. He looked over just in time to see Sam swooping down and capturing Casey's perfect pink lips. Trying to control the sudden surge of jealousy that flashed through him, Derek growled and bruisingly crushed his lips against Emily's.

If he closed his eyes and didn't concentrate, he could pretend he was kissing the one he _wanted_ to be kissing.

As soon as Sam released Casey, she looked over and tried to hide her frown as she saw her stepbrother making out with her best friend. His eyes were closed and he looked like he was really into it, too. Swallowing her feelings, she got into Sam's car, waiting for the two to be done so this awful night would come to an end.

Even in the car, Derek and Emily were making out. Casey kept her teeth clenched together and angrily stared out the window at the houses passing by as they drove on.

That's when she heard it.

"_Casey_…" Derek moaned from the back. Instantly, Casey snapped her head to look at her stepbrother with wide eyes. Emily quickly pushed Derek away from her, her own eyes wide with confusion. Even Sam took his eyes off the road to look back at Derek, his forehead creased.

"_What_!" Emily demanded, looking from Derek to Casey.

_Shit_ was all Derek could get through his head. _Shit…shit…shit…_

"Uh… Casey... I was…uh…just wondering if you had the house keys," Derek made up quickly. "I realized that I forgot them."

Casey immediately looked at Emily to see if she bought it. Her best friend, God love her, was as flaky as they come. She bought it right away. But Casey didn't dare to breathe yet, looking over at her boyfriend.

His face didn't register anything, and his eyes were back on the road. Casey couldn't tell if it was a good sign or a bad sign. Deciding to take it as a good one, Casey let herself relax.

And, as Emily began rambling about who-knows-what, Derek closed his eyes briefly in relief. That had been a close one.

Derek walked Emily over to her house once Sam parked his car in front of the MacDonald-Venturi household. Casey made sure to initiate a long kiss goodnight, hoping that he wasn't suspicious or anything. He kissed her back, and she was glad for that. Derek came back over to her once Emily had gone into her own house.

Together, Derek and Casey both waved to Sam as he drove away.

"_Close one_!" Casey exclaimed as soon as Sam was out of viewing range. She punched Derek in the shoulder.

"Sorry!" he growled, rubbing his arm where she had hit him. "Geez, you've got a good arm, woman."

"And don't you ever forget it," she smiled triumphantly, her anger seemingly dissipating abruptly. "That was a hell of a double date, huh?"

He chuckled, shaking his head in agreement as they quietly went into their house. It was late, and most, if not all, of their family would be sleeping. "It was the epitome of suckage."

Casey snorted. "The epitome of suckage?" she asked him quietly in the dark. "You're so weird."

"Weird but hot," Derek smirked cockily as they went upstairs together.

"I'm not going to disagree," Casey said coyly as they walked over to their rooms. She bit her lower lip, staring at Derek in the dim light. "Were you thinking of me while you were kissing Emily?"

"Always," Derek answered honestly, reaching out and tucking a loose strand of hair behind her ear. Casey smiled at his admission.

Derek reached over and took her by the waist, pulling her towards him gently and finding her lips. She closed her eyes, instantly growing weak as he kissed her. Sam Kisses could never compare with Derek Kisses. Ever.

"Mmm…" she moaned happily as his tongue slid into her mouth. He reached up and began tugging at the bottom of her shirt, but Casey reluctantly stopped him with her hand.

"I'm sorry, Derek…" she murmured apologetically. "I'm just really tired…"

"It's okay," Derek released her and pressed a kiss to the crown of her head. "I am, too. Especially after that double date from hell."

Casey muffled a laugh. "No kidding… rain check?" she asked, searching his eyes in the darkness.

"Definitely," he said, and they kissed one last time before going to bed in their separate bedrooms.


	4. Chapter 4

**Author's Note: **_Aww, thank you to everyone who reviewed the last chapter, I really appreciate it! Here's the next part for those loyal readers! You all rock!_

* * *

The next morning was Saturday morning, Derek's favorite part of the entire week. It was the one day that he could sleep in with no interruptions. He looked forward to it all week long. 

Casey knew this, so at 9AM, which was like 5AM in DSMT--Derek's Saturday Morning Time, she snuck into his bedroom and evilly jumped on his bed, waking him up.

He glared at her through blurry eyes. "God, Case, come on… it's so early, I—"

Casey cut him off by pressing her lips against his, taking advantage of his opened mouth and sliding her tongue against his. He gave in instantly, knowing that he would never reject her kisses, even if it was _4_AM on a Saturday.

He moaned, letting his eyes fall shut as Casey deepened the kiss, shifting her body to now lie on top of him. He was definitely fully awake now.

"Mmm… Case…" Derek managed to groan in pleasure as her lips now moved along his jaw line. He grabbed her hips and pressed her tightly against him, letting her feel just how much he was enjoying this.

She smiled, pulling up his shirt and raking her nails down his bare chest until he let out a hissing sound. She wiggled around on top of him, slowly torturing him as she peppered open-mouthed kisses across his chest.

"Casey, I want you so bad…" Derek moaned as her kisses now moved down his torso. He ran his fingers through her soft hair and then moved down to the hem of the short top she was wearing. She let him pull it up and over her head and he licked his lips at the sight.

She didn't say anything, but Derek could see the lust and desire in her deep blue eyes. Quickly rolling them over so she was now on the bottom, he began to ravage her body.

They didn't hear the knock on the door. Or the door opening.

But they did hear the shriek.

"DEREK! _CASEY_!"

Derek and Casey quickly snapped their heads over to the doorway, where Emily just happen to be standing. Her eyes were wide and filled with shocked tears, and her face was quickly turning red with anger.

Casey's jaw dropped at having being caught. She scrambled to hide her half-nakedness and Derek could only stare at his girlfriend guiltily.

"Emily!" Casey had yelped. "It's, uh, it's not what you think!" she exclaimed lamely.

Emily just glared from one teen to the other. Her boyfriend and her best-friend. Tears of rage splashed down her cheeks. "How COULD you!" was all she said in an eerily calm but angry tone. She ran off before either Casey or Derek had a chance to say anything.

Not that there was anything to say.

Derek and Casey just remained where they were on the bed, both of them guiltily silent.

"Shit," Derek finally swore, raking his hand through his mussed hair. This was not good. He looked over at Casey, who had this terrified look on her face. Her eyes swam with tears.

"She's going to tell Sam," she said softly, not meeting Derek's eyes. "And he's going to hate us. The two of them are going to hate us."

"It looks like Emily already does," Derek said with a heavy sigh.

Casey finally looked over at Derek, her eyes distant and cold. "We should have never started this," she said stonily and yanked her shirt back on before hurrying out of the room.

Derek sat on his bed in shock. What did Casey mean by that? Was it this morning's make-out session that she regretted? Or was it… _everything_ that she regretted?

Had he just lost his best-friend, his girlfriend, and his secret love all in about two minutes time?

* * *

Casey sobbed in the shower so nobody could hear her. The water drowned out the sounds that escaped her lips. Her best-friend—who was really her ONLY friend—now _hated_ her. Her boyfriend would surely be _dumping_ her. And all for what? A stupid affair with her _stepbrother_! 

WHAT had she been THINKING when she started this affair with Derek in the first place? It could never go anywhere. They were step-siblings. They both had significant others. All it was was hormones and lust. That's all. And now she had no best-friend and no boyfriend because of it.

Sure, Derek was hot. And he had amazing lips and a great body. And he could be sweet when he when he wanted to be. But he was her _stepbrother_. Hello, _incest_! Her mother and his father were MARRIED. She considered his brother and sister to be _her_ brother and sister.

So it was like she was making out with her _brother_!

And it was more than making out. In the past, they had gone past first base, rounded second base and even third. In fact, the way they were going, they would have probably been heading home within the next few minutes—that is if her _best-friend_ and his _girlfriend_ hadn't walked in on them.

Stupid. Stupid, stupid, _stupid_ Casey.

On top of that, she was beginning to have actual _feelings_ for her stepbrother. Yes, she had been trying to keep it purely physical and allow herself only to feel lust for him. But that could only go on for so long before things started to change.

She had begun looking forward to seeing Derek more than her own boyfriend. She had let Derek go further with her than her own boyfriend. And she had started to think about having sex… and not with her boyfriend, either.

Whenever she had racy dreams, they were about Derek. Whenever she pictured herself happily married with children, the kids all looked like little Dereks.

It was wrong. She had a boyfriend—Sam—who loved her and treated her like a princess—most of the time, anyway. And she wasn't supposed to be feeling these type of feelings about her stepbrother. It was SO wrong.

And yet, whenever she was with Derek… it felt so right.

Maybe having Emily catch them was a sign. A sign that she was getting in too deep. A sign that she had to end things, and end them now before she got in over her head.

So she called it off with Derek and ran into the shower to cry her eyes out. For now she had to ignore him and spend as little time as possible with him.

And get over him. Before she got her heart broken in the end.

* * *

Derek didn't see Casey for the rest of the morning. She didn't come down for lunch, either. It wasn't until dinner that he actually saw her. She sat across from him as she usually did. 

She stared down at her dinner sullenly the whole time.

He had tried to catch her eyes several times, to no avail. He even tapped her foot under the table to try to get a response out of her. Nothing. She didn't even look at him.

After dinner, Derek heard Casey on the phone with Sam. He tried to eavesdrop, but all he heard were muffled cries and shouting. It most likely wasn't good. Derek received an instant message from Sam that was very…_colorful_. He was impressed at some of the words that Sam knew… he had never heard them come out of Sam's mouth before.

It was clear that they were definitely _not_ best-friends anymore. Or friends. In fact, Sam basically said that he never wanted to see Derek again—in harsher words, of course.

And it was also clear that he and Emily were over.

But Derek wasn't that upset about Emily. He had never liked her that much anyway. And Sam… he and Sam had been great friends for years, that is true, but still, Derek wasn't as upset over at his was about something else…or _someone_ else, in particular…

Casey. He had fallen in love with her. He had realized that a long time ago. It killed him to see her with Sam. But knowing that she was his in secret—that was the only thing that kept him from going crazy on Sam.

He couldn't remember how their "secret affair" had started. Or when. It started with the fighting… then it went to bantering… then flirting… subtle touching… kissing… making-out… and other things. They had almost had sex a few times. And he had a hunch that it had been heading that way this morning. And then Emily showed up.

He never thought that she would come over unannounced, early in the morning. Had she even knocked? He couldn't remember… all of his senses had been taken over by Casey.

And now Casey hated him.

Derek knew that he should leave her alone, but that night he knocked on her door anyway.

"Who is it?" Casey asked, her voice strange.

"It's me," he said quietly, praying that she would let him in.

"Go away, Derek," she said in a cold voice.

"Case, I just—"

"Go away!" she shouted, and he heard something being flung against the door. He backed away from the door at that.

"Fine," he spun on his heel and went back to his room, slamming the door shut.

Yeah, they were definitely over.


	5. Chapter 5

**Author's Note: **_Here's the last chapter! This chapter gets a little... err heated towards the end... not explicit, though. But still, just to warn you ;-) Well, hope you've enjoyed this even though it was a lil bit different from my usual stories... look for more LWD stories from me coming soon!_

* * *

Casey couldn't sleep. She tossed and turned for half the night before giving up completely. She would just have to look like hell tomorrow. 

All she kept hearing was Sam yelling at her on the phone. He had broken up with her, as expected.

And all she kept seeing was the hurt look on Derek's face when she ignored him at dinner.

She had cried until there were no tears left. She didn't know what she cried more for—losing Emily, losing Sam, or losing Derek.

She had a feeling she was more upset about losing the one she shouldn't have had a relationship with in the first place.

She should have just kept it as a step-sibling, barely existent kind of relationship. Or even one of those sibling love/hate relationships. But no, she had to let her hormones lead her right into Derek's arms—and onto Derek's warm, full lips.

Casey groaned, sitting up in bed and turning the lamp next to her on. She had to stop thinking about Derek. She had to either not think of him at all, or at least start thinking of him as a brother—the way it SHOULD be.

But it had been so hard to tell him that he couldn't come in that night, to push him away, to tell him to leave her alone. It had to be done, but it was so incredibly hard. She wanted nothing more than to let him come in and take him into her bed and let him hold her. She always felt so safe in his arms—so _wanted_. He was the only one that made her stomach do flip-flops.

Yes, not even Sam did that.

She should have realized it then that she was getting in too deep with her stepbrother. Keyword being "_brother_."

At the same time, Derek was lying in his own bed, staring at the ceiling, unable to sleep. All he could think about was Casey. He couldn't believe that they were over. This relationship that nobody had known about—well, until now—had been the best thing in his life. Casey had been good for him. She made him smile, made him laugh. Let him be himself without having to always act all cool and suave like he did in school.

And now it was over, just like that. No more late night cuddles or early morning make-out sessions. No more silly tickle fights or forbidden flirting.

His heart ached for the first time.

Not able to stand lying in the dark room, listening to his own thoughts in the deafening silence, Derek left his bedroom and walked downstairs into the living room. The whole house was quiet, so, before his thoughts could get at him again, he turned the TV on and sat back in his favorite recliner, drowning himself in mindless television just to try to rid the pain of his broken heart.

* * *

Casey walked down stairs to get herself something to eat. Her stomach was rumbling because she hadn't eaten much at dinner and it wasn't like she was sleeping anyway. Her eyebrows furrowed when she heard the TV on. What was somebody doing up at this hour? 

She padded into the living room and found Derek sitting there, his eyes glued to the television as if he had never seen that particular McDonald's Happy Meal commercial before. She tried to will herself to keep moving into the kitchen, but her body just stayed there, frozen in place, staring at his motionless form.

He didn't even seem to be blinking.

"Derek?" she found herself asking, her soft voice nearly lost in the sound of the television.

But Derek heard her. His eyes quickly moved away from the television and he looked at her. Surprised to see her, he just said her name. "Casey."

She bit her lower lip. Maybe it had been a bad idea to come downstairs in the first place. "Uh… are you okay?" she asked awkwardly.

"Just dandy," he said sarcastically, his voice turning gruff and his eyes narrowing.

Casey swallowed uncomfortably. "Uh… okay then…" she quickly bolted into the kitchen to avoid anymore of the conversation. She numbly made herself a peanut butter and banana sandwich and sat down with it and a glass of milk. She ate in the dark, slowly and soundlessly.

She was almost finished when Derek burst in, causing her to drop her sandwich in surprise.

"Casey, I don't give a damn about Emily or Sam. And I don't care how screwed up this whole thing is. Or how much you hate me right now. Because I need to tell you this," he grabbed her hands. "I love you."

Casey's jaw dropped open.

"I love you and I want you and I know you don't love or want me, but I needed to tell you that because my heart hurts and I just want the pain to _stop_," he said each word forcefully, intently staring right into her eyes in the dimly-lit room. They stared at each other for a long three seconds before breaking eye contact.

Derek, feeling glad to get it off of his chest, dropped Casey's hands and left just as quickly as he had come in.

Casey just sat there frozen, her eyes wide and mouth still hanging open.

And, in the dark shadows of the kitchen, crouched down under the counter, a young girl gave her stepbrother a triumphant smirk.

* * *

Casey lied back down in her bed, a million thoughts racing through her mind. But one thought rang above them all: Derek… _loved her_? 

It was wrong. So wrong. They loved each other… and not in a brotherly-sisterly way. Not in the way that they _should_ love each other. Not in the way Edwin and Lizzie loved each other, or in the way Marti loved Derek. Not in the way Sam loved his sisters and Emily loved her little brother. Not in a way that was at all conventional or right in any way.

Derek sat on the floor of his room, absentmindedly twirling a hockey puck in his hand, thinking about Casey. He had told her that he loved her. He hadn't meant to do it… but his heart had practically demanded that he did. He had never experienced this type of aching before… this brokenness.

And he didn't like it one bit.

He thought if he got it off of his chest that it would go away. It didn't. As he sat there in his bedroom silently, the pain still lingered.

He looked up, startled as he saw his door gently push open and Casey's face appear out of nowhere. She immediately found him on the floor and gave him an unreadable look.

"Can I come in?" she asked quietly, but her voice seemed so loud in the stillness of the night.

Derek nodded, not making a move. He was curious, but didn't want to appear overtly so. What was she doing here?

Casey shut the door softly behind her and rested her back upon it, afraid to come too close to her stepbrother. "Uh… I think we need to talk."

"I already said all that I had to say," Derek replied. But his words weren't harsh or firm, only matter-of-fact. Passive. Emotionless.

Casey nodded slowly. She knew that this wasn't going to be easy. "Derek… this whole thing… we should have never started it. It's wrong on so many levels. We both knew that it could never be," she looked away from him, over at the records on his wall. Anywhere but his eyes. "All we ended up doing is getting ourselves hurt and hurting the people around us."

Derek grew angry at that. He stood up and in two strides was right in front of Casey, causing her to flatten against the door in surprise at his sudden movement. His eyes flashed with anger. "So it was nothing to you, Case? Just some kind of… hormonal release for you?" his words were biting. She actually winced as he spoke them.

But she said nothing. So he continued.

"What was it, Case? Were you just letting out your sexual frustrations on me? Getting back at Sam for being so slow?" he growled. She looked away and he grabbed her, forcing her to look at him.

"Derek, please…" she said softly, her eyes filling up with tears.

"Are you trying to tell me that you felt nothing?" he glared at her pointedly. "Say it, Case. Tell me that you feel nothing for me." He was challenging her, egging her on. She had never seen him look so angry before.

"Tell me that you feel nothing," he quickly crushed his lips against hers. He pried her lips apart in order to thrust his tongue into her mouth, forcing all of his anger out. Casey could do nothing, not even able to move away.

She wasn't sure if she wanted to, either.

Her tears slipped down her cheeks as Derek grabbed her by her hips, his fingertips digging into her flesh painfully.

"Say it, Casey," he demanded against her lips.

She still didn't reply. He pulled her towards his bed and pushed her down. She didn't fight him as she felt the weight of his body on top of her, crushing her. His mouth vigorously began sucking on the side of her neck as his fingers began hastily unbuttoning her shirt one button at a time.

"Say it," he commanded, his teeth biting into her soft skin, sure to leave his mark on her. She let out a whimper, but still didn't speak. He got her pajama shirt off and grabbed the waistband of her pajama pants, ripping them off of her quickly.

Casey's mind screamed "Incest!" But her voice didn't sound.

Derek kept trying to incense her, insisting her to say that their relationship had meant nothing to her. But she just watched, tears rolling down her face, as he yanked off his own clothes.

When they were both naked, Derek grabbed Casey's wrists, pinning them above her head on the bed so she couldn't move.

"Say it," he said one last time. And this time, it wasn't harsh… it was more of a pleading.

"I can't," Casey's strangled voice came barely above a whisper.

Derek's body stilled above hers, taken off guard. "Why not?"

Casey's lower lip trembled. "I… I…"

And Derek's grip on her loosened. Because suddenly he knew. His face softened in realization. "Say it Casey, please…" he whispered, gently pressing little kisses all around her face, kissing away her tears, his whole demeanor changing in an instant.

"I love you," she finally murmured.

Derek felt his heart clench and stopped kissing Casey to look deep into her glimmering blue eyes. He felt her right hand try to move so he quickly released it, and she ran her hand through his sweat-matted, wild hair before cupping his cheek.

"I love you so much, Derek," she whispered, her eyes directly on his. "I'm just so scared that it's not right…"

"It _is_ right," he told her insistently, his voice soft as he lovingly nuzzled her. "It's right, baby."

She closed her eyes at his gentle touch. "But Sam and Emily… and our parents…" she began to protest.

"Shhh," he chided her, pressing his lips against her forehead. "It doesn't matter. None of it matters. I love you."

Casey gave him a gentle smile. "Make love to me, Derek," she whispered, tracing his lips with her fingertip.

Derek smiled back at her, eager to comply with her wishes.

And the two of them decided that they didn't really care about who knew about their dirty little secret.

* * *

**the end! feedback very appreciated!**


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